Last year, 53 underclassmen declared. There were 46 in 2009, 53 in '08, 40 in '07, 48 in '06, 49 in '05, 43 in '04, 54 in '03, 43 in '02, 54 in '01 and 31 in 2000.

Today, we'll look at the players who are most likely to fill the shoes of the departing underclassmen. In some cases, coaches won't have to worry. In other cases, though, the coaches should be sweating -- profusely.

In each case, we're also including a "replacement quotient," a gauge as to how hard that player will be to replace. A five-star quotient means it's going to be extremely difficult; a one-star quotient is the equivalent of saying, "Who was it that left again?"

While the NFL certified 56 underclassmen, we are not including the three from North Carolina -- DT Marvin Austin, WR Greg Little and DE Robert Quinn. Each was suspended for the 2010 season, meaning the Heels already have had to replace them.

DE Marcell DareusThe buzz: Two touted junior college defensive linemen -- Quinton Dial and Jesse Williams -- already are enrolled and will be closely watched during spring drills. Holdovers Damion Square, Undra Billingsley, Darrington Sentimore and Brandon Moore also will be in the spotlight during spring ball. While Dareus was talented, the Tide have ample candidates for his vacated spot and will be fine along the defensive front.
Replacement quotient: 3 stars

RB Mark Ingram
The buzz: Ingram's departure opens the door for junior-to-be Trent Richardson. He has rushed for 1,451 yards in his two seasons with the Tide, and he should be expected to match that this fall. That means next year at this time, we'll be talking about who will replace Richardson after he takes his talents to the NFL.
Replacement quotient: 3 stars

WR Julio Jones
The buzz: He is going to be the early entrant that the Tide has the most trouble replacing. The bodies are there, but there will be a talent drop-off. Seniors-to-be Darius Hanks and Marquis Maze will vie in spring practice to become the go-to guy, and the Tide also need someone to emerge as the No. 3 guy behind that duo. Kenny Bell, Brandon Gibson and Kevin Norwood are the leading candidates, and expect a true freshman to get into the mix in the fall.
Replacement quotient: 5 stars

DT Lawrence Guy
The buzz: Guy was underrated nationally and did a solid job in the middle of the line for the Sun Devils. His departure means Arizona State must replace both starting defensive tackles, and that is, by far, the biggest hole facing coaches as they prepare for spring drills. Look for Corey Adams, Toa Tuitea, Bo Moos and William Sutton -- a starter in 2009 who was ineligible in 2010 -- to be the top four at tackle. Arizona State relies on its linebackers to make plays, and any problems in the interior of the line also will mean problems for the linebackers.
Replacement quotient: 4 stars

QB Ryan Mallett
The buzz: His decision shouldn't have surprised anybody. Next up at quarterback for the Hogs will be Tyler Wilson, who played extensively in just one game but threw for 332 yards and four TDs (and also two picks) in a loss to Auburn. Wilson was 34-of-51 for 453 yards on the season. Coach Bobby Petrino isn't going to change his offense, but you may see some tweaks to put a bigger burden on the rushing attack with Knile Davis returning at tailback. Mallett was the centerpiece of the 2010 offense; it's hard to imagine Wilson being the centerpiece of the '11 attack with Davis on hand.
Replacement quotient: 4 stars

WR Darvin Adams
The buzz: Adams was the Tigers' leading receiver, and his surprising departure means three key wide receivers need to be replaced. Junior-to-be Emory Blake will become the Tigers' go-to guy and an All-SEC candidate, and senior-to-be Quindarius Carr and junior-to-be DeAngelo Benton -- who arrived highly hyped but hasn't done much -- need strong spring practices. Benton and Carr combined for four catches this season. Senior-to-be Derek Winter and numerous underclassmen also need to impress during spring drills. The Tigers expect to sign at least two receivers next month and each can be expected to get a shot in the fall.
Replacement quotient: 4 stars

DT Nick Fairley
The buzz: Fairley was the nation's most dominant defensive tackle this season and will be impossible to replace. His decision to go pro means Auburn is losing three of its top four defensive tackles. Sophomore-to-be Jeffrey Whitaker has a big upside and is a sure starter. Another sophomore-to-be, Kenneth Carter, probably is the front-runner for the other starting spot. But the No. 2 jobs are in question, which means spring practice will be huge for the defensive front.
Replacement quotient: 5 stars

QB Cameron Newton
The buzz: Newton can't be replaced. But coordinator Gus Malzahn is savvy enough to tweak the offense to lessen the importance of the quarterback having to make plays. Junior-to-be Barrett Trotter will head into spring practice as the new starter, with sophomore-to-be Clint Moseley hoping to show enough to be the No. 2 guy. Highly touted freshman Kiehl Frazier will be on hand in the fall, and if either Trotter or Moseley struggle during spring ball, expect to see Frazier on the field during the 2011 season.
Replacement quotient: 5 stars

RB Shane Vereen
The buzz: There seemingly is an assembly line for running backs in Berkeley, and Vereen is the latest off that line. But the next "model," if you will, is a huge question. Junior-to-be Isi Sofele was the main backup this season, but he's just 5 feet 8 and there are questions about whether he can be a 20-carry-a-game guy. The other holdovers who will look to make a splash in the spring are Covaughn DeBoskie-Johnson, Dasarte Yarnway and Trajuan Briggs. Cal expects to sign three tailbacks next month, and at least one can expect some carries this fall.
Replacement quotient: 4 stars

DE Da'Quan Bowers
The buzz: Bowers led the nation with 15.5 sacks, and no one player on the Tigers' roster is going to match that this fall. Junior-to-be Malliciah Goodman and senior-to-be Kourtnei Brown figure to get first dibs on Bowers' vacant spot. Depth at end is dicey, which is why two early entrants who play the position need to show something during spring practice. Hopes are especially high for Corey Crawford, who spent this past season at Chatham (Va.) Hargrave Military Academy.
Replacement quotient: 5 stars

RB Jamie Harper
The buzz: His departure was somewhat of a surprise, as he never has been a full-time starter. He rushed for 1,311 yards and 12 TDs in his career. Speedy junior-to-be Andre Ellington will be the Tigers' feature back in 2011, with sophomore-to-be Roderick McDowell also on hand. Five-star freshman Mike Bellamy arrives in the fall and will see time; how much time depends on McDowell.
Replacement quotient: 3 stars

RB Jordan Todman
The buzz: Todman was the centerpiece of the Huskies' offense, and the top spring priority for new coach Paul Pasqualoni better be on how to diversify UConn's offense. Senior to-be Robbie Frey has his moments as Todman's backup this season, and developing depth behind Frey is going to be vital for the Huskies.
Replacement quotient: 5 stars

FS Will Hill
The buzz: The Gators will have two new starting safeties next season, but it will be a heck of a lot easier replacing Hill than replacing SS Ahmad Black, a senior who was Florida's best player this season. Look for junior-to-be Josh Evans to move into Hill's vacated spot. Evans started two games this season when Hill was suspended, and while Evans doesn't have Hill's vast physical gifts, he should provide a steadying influence that Hill -- known for his freelancing ways -- didn't provide in 2010.
Replacement quotient: 2 stars

WR Jamel Hamler
The buzz: He was the Bulldogs' leading receiver this season, but his decision to turn pro was a surprise. Still, the Bulldogs have a lot of bodies at wide receiver and now need one of those players to step up to be the go-to guy. Rashad Evans, Jalen Saunders and A.J. Johnson are the leading contenders. Depth looks fine.
Replacement quotient: 3 stars

WR A.J. Green
The buzz: He was the Bulldogs' best offensive player this season and will be sorely missed. He was suspended for the first four games this season and the passing attack struggled as a result. The Bulldogs must find a new go-to guy in spring drills. Junior-to-be Tavarres King likely gets first dibs; he has 47 receptions in two seasons. Coaches also need to see something from junior-to-be Marlon Brown, a big-time recruit who basically has been invisible in his first two seasons (13 total receptions).
Replacement quotient: 5 stars

OLB Justin Houston
The buzz: He was the Bulldogs' best defender this season, and he, too, will be sorely missed. Georgia had 24 sacks as a team and Houston had 10 of them. The Bulldogs have to replace three of their four starting linebackers, including both starters on the outside, where they look particularly weak. Cornelius Washington is the only returnee on the outside who saw much time this season. Former walk-on Reuben Faloughi, Brock Boleman, T.J. Stripling, Chase Vasser and USC transfer Jarvis Jones are others who figure to be in the mix during spring ball. Jones has had neck problems. Expect a freshman to get a shot in the fall, as well.
Replacement quotient: 5 stars

OT Nick Claytor
The buzz: His departure was a surprise. Junior-to-be Phil Smith, a part-time starter this past season, looks like a lock to start at one tackle spot. The other side is a huge question mark.
Replacement quotient: 4 stars

S Jerrard Tarrant
The buzz: His departure might have been even more surprising than Claytor's. Tarrant's decision means Tech needs two new starting safeties. Sophomores-to-be Isaiah Johnson and Jemea Thomas and senior-to-be Rashaad Reid seem the likely candidates. Depth could be an issue, though.
Replacement quotient: 2 stars

RB Mikel Leshoure
The buzz: Leshoure was one of the nation's best backs this season and, like all the Illini underclassmen who are leaving, is going to be missed. Seniors-to-be Jason Ford and Troy Pollard and redshirt freshman Bud Golden will get opportunities during spring ball to show they deserve to be the feature back. Ford is the leading contender. The Illini are likely to sign at least two freshman running backs next month, and one could play this fall.
Replacement quotient: 5 stars

DT Corey Liuget
The buzz: Liuget would've been one of the nation's best defensive linemen had he stayed in school; as such, he's going to be tough to replace. Akeem Spence was solid as a redshirt freshman this season and again should start. Junior-to-be Glenn Foster, senior-to-be Daryle Ballew and redshirt freshmen Austin Teitsma and Jake Howe are the likely candidates for the other starting role.
Replacement quotient: 4 stars

LB Martez Wilson
The buzz: Wilson's departure means the Illini need two new starting linebackers. Coaches are high on sophomore-to-be Jonathan Brown, who played a lot this season. Senior-to-be Ian Thomas is the lone returning starter at linebacker, and sophomore-to-be Brandon Denmark needs a strong spring to prove he belongs in the starting lineup. Depth could be an issue if some of the younger players, such as Earnest Thomas, struggle.
Replacement quotient: 4 stars

WR Tandon Doss
The buzz: Doss was the Hoosiers' No. 2 receiver but had the most receiving TDs, with seven. The new coaching staff can count on Damarlo Belcher and Duwyce Wilson, but still will miss Doss, who would've been a great fit for what new coach Kevin Wilson -- who had been Oklahoma's offensive coordinator -- wants to do. Sophomore-to-be Kofi Hughes is a guy to watch in spring ball. TE Ted Bolser should enjoy the new offense, as well, and his production should climb, easing the loss of Doss.
Replacement quotient: 4 stars

SS Tyler Sash
The buzz: Iowa will have one of the best cornerback duos in the nation next season in Micah Hyde and Shaun Prater, but Sash's decision means the Hawkeyes will have two new starting safeties. Senior-to-be Tom Donatell likely gets first dibs at Sash's spot, while sophomore-to-be Tanner Miller looks to be the new free safety (replacing senior Brett Greenwood). Nick Nielsen and maybe Jordan Bernstine also will be in the mix.
Replacement quotient: 4 stars

WR Randall Cobb
The buzz: His departure is a huge blow to a UK offense that lacks playmakers. Cobb was one of the best receivers in the nation and was a do-it-all guy for the Wildcats, who also are losing starting WR Chris Matthews. Junior-to-be LaRod King seems likely to be the go-to receiver next season, but the identities of the No. 2 and 3 receivers are up in the air. Candidates include Matt Roark, Brian Adams, Aaron Boyd and E.J. Fields. UK is likely to sign at least three wide receivers next month, and one of those will need to produce this fall.
Replacement quotient: 5 stars

CB Patrick Peterson
The buzz: To no one's surprise, Peterson is going pro, and is a lock to be selected in the first round. Sophomore-to-be Tyrann Mathieu made a big splash as a true freshman and he's likely to replace Peterson as the Tigers' "star" cornerback, Junior-to-be Morris Claiborne should be the other starter, with sophomore-to-be Tharold Simon also seeing a lot of time. The Tigers are bringing in a big-time freshman crop at the position, and one or two of those guys figure to see time in the fall.
Replacement quotient: 4 stars

RB Stevan Ridley
The buzz: His departure was surprising. Still, the Tigers look to be in a position to withstand his departure. Sophomores-to-be Spencer Ware -- who had a big Cotton Bowl against Texas A&M -- and Michael Ford will fight it out during spring practice for the starting job. Sophomore-to-be Alfred Blue also hopes to get into the mix. LSU is bringing in two four-star running backs, too, and one of those will play in 2011.
Replacement quotient: 3 stars

WR Torrey Smith
The buzz: Smith's departure wasn't that big a surprise but it certainly hurts, as the Terps don't have a returning receiver who caught more than 16 passes this season. That would be senior-to-be Quintin McCree. Senior-to-be Ronnie Tyler and junior-to-be Kevin Dorsey must step up in spring practice. Redshirt freshman Adrian Coxson, who signed with Florida last year but left for Maryland in August, will be closely watched by the new coaching staff in spring drills. While new coach Randy Edsall was known for his rushing attacks at Connecticut, new offensive coordinator Gary Crowton has a passing background.
Replacement quotient: 4 stars

CB Brandon Harris
The buzz: Harris was a key component of a productive UM secondary, which will have to replace its top three corners. Junior-to-be Brandon McGee should nail down one of the spots, but the other one is up for grabs. Redshirt freshmen Devont'a Davis, Kacy Rodgers and Keion Payne will get their chances to impress the new coaching staff in spring drills. Expect a true freshman to see time this fall, too.
Replacement quotient: 4 stars

QB Blaine Gabbert
The buzz: Gabbert didn't have a great season statistically, but he will be the first or second quarterback taken in the NFL draft, so his decision wasn't a surprise. Sophomore-to-be James Franklin will be the new starter; he's a good athlete with a nice arm. His backup will be determined in spring ball. Sophomore-to-be Ashton Glaser might have the inside track, with redshirt freshman Tyler Gabbert -- Blaine's brother -- also in the hunt.
Replacement quotient: 4 stars

DE Aldon Smith
The buzz: Smith had an injury-plagued 2010 but still decided to go pro. The Tigers seem set at the starting end spots with Brad Madison and Jacquies Smith, who combined for 13 sacks this season. Depth will come from Michael Sam and Brayden Burnett. Redshirt freshman Kony Ealy has a chance to earn time during spring practice.
Replacement quotient: 3 stars

TE Kyle Rudolph
The buzz: If the Irish were going to lose one player between Rudolph and WR Michael Floyd, Rudolph would've been the one the coaches picked. Rudolph is talented, but Floyd is truly special. Rudolph missed the final seven games of the season, and junior-to-be Tyler Eifert performed well in his stead. Mike Ragone's status is up in the air; he could return for a fifth season and be the backup. Others in the mix at tight end will be Jake Golic and Alex Welch. Touted freshman Ben Koyack is set to arrive in the fall and almost certainly will see time.
Replacement quotient: 3 stars

FS Javes Lewis
The buzz: His departure was quite surprising, considering he was a backup who started just once this past season. He did have a strong 2009 season, though, starting at both corner and free safety. The upshot, though: Oregon needs backups at both safety spots now, and figure some combination of Brian Jackson, Marcus Davis (a Texas transfer) and Erick Dargan to fill the bill.
Replacement quotient: 2 stars

RB Jacquizz Rodgers
The buzz: This is a huge loss, as big as any on this list. Rodgers had 256 carries and 1,184 yards. The leading returning running back is senior-to-be Ryan McCants, who had four carries and 14 yards this past season. Junior-to-be Jordan Jenkins also will be in the running, and he has four carries for 14 yards in his career. Holdovers Malcolm Marable and Jovan Stevenson also will get opportunities during spring drills, as will Terron Ward, a grayshirt from last year's signing class who enrolled earlier this month; his brother, T.J., is a former Oregon safety. The Beavers expect to sign at least two running backs next month and there's a chance both could see the field this fall.
Replacement quotient: 5 stars

WR Jonathan Baldwin
The buzz: Baldwin was underutilized this season but still led the team in receiving and really will be missed considering the offensive attack favored by new coach Todd Graham. Baldwin would've been a threat to have 80 catches under Graham. Junior-to-be Mike Shanahan and sophomore-to-be Devin Street should be the main contenders to be the new go-to receiver. Junior-to-be Cameron Saddler, who is 5 feet 7, could be a nice fit as a slot guy in the new offense. Pitt had done a nice job under former coach Dave Wannstedt in bringing in wide receivers, and all those guys are going to get far more opportunities now.
Replacement quotient: 4 stars

FB Henry Hynoski
The buzz: Hynoski was a devastating lead blocker and a good outlet receiver. His receiving skills would have been a nice fit for the new offense at H-back. Alas, his departure really doesn't hurt that much.
Replacement quotient: 2 stars

RB Dion Lewis
The buzz: While Graham has a reputation as running a wide-open offense, Tulsa was balanced between the run and the pass, meaning Lewis would've gone ample opportunities to run the ball. In addition, Lewis is a solid receiver and those skills will be missed. Regardless, his departure won't hurt as much as Baldwin's. Junior-to-be Ray Graham ran for 922 yards this past season and should approach the 1,000-yard plateau again. He also had 24 receptions in 2010 and will get at least that many this fall. The fight for the backup role will be a good one during spring ball, with junior-to-be Chris Burns probably the leading candidate.
Replacement quotient: 3 stars

WR Tori Gurley
The buzz: Gurley was the Gamecocks' No. 2 receiver this fall, and he provided another physical target to team with Alshon Jeffery. There are a number of candidates to be the new No. 2 guy. Senior-to-be Jason Barnes was non-existent this past season, with just six receptions, after catching a combined 53 passes the past two seasons. Junior-to-be D.L. Moore seems the likely candidate, though sophomores-to-be Ace Sanders and Lamar Scruggs also will get chances in spring practice. The Gamecocks seem likely to sign at three wide receivers next month, and it wouldn't be a surprise if one of them gets ample playing time in the fall.
Replacement quotient: 3 stars

WR DeAndre Brown
The buzz: Brown has a ton of talent, but for various reasons, including nagging injuries, he never really showed that talent on a consistent basis. He was seventh on the team in receptions this past season. Senior-to-be Kelvin Bolden or junior-to-be Quintin Pierce will be QB Austin Davis' go-to guy this fall, and depth looks fine.
Replacement quotient: 2 stars

OLB Thomas Keiser
The buzz: His departure was a surprise and means the Cardinal now have to replace five defensive starters. Sophomore-to-be Blake Lueders likely fills the vacant hole, though junior-to-be Alex Debniak is another possibility. Look for a freshman to get playing time in the fall at the position.
Replacement quotient: 4 stars

DT Muhammad Wilkerson
The buzz: The disruptive Wilkerson was a big-timer in the middle of the line for the Owls, who now have to replace both starting defensive tackles. Senior-to-be Levi Brown is a good bet at one of the spots, but the other is up in the air. There's a new coaching staff that could move some players around up front, so the revamped defensive line is going to be a main story line in spring practice.
Replacement quotient: 5 stars

CB Aaron Williams
The buzz: Williams had an uneven season, but he still will be missed. His decision means Texas will be missing its top three cornerbacks from this past season. Junior-to-be Kenny Vaccaro played safety and nickelback last season but could move to corner. Sophomores-to-be Eryon Barnett, A.J. White and Carrington Byndom are the other leading contenders. Texas, which got just one interception from its cornerbacks this past season, also looks as if it is going to sign four cornerbacks next month, so expect two of those to get into the mix in the fall.
Replacement quotient: 4 stars

LB Akeem Ayers
The buzz: Ayers had a great 2009 season but wasn't quite as productive in 2010. Still, any kind of talent drain hurts the Bruins. The linebacker corps has a chance to be good, with sophomores-to-be Patrick Larimore and Jordan Zumwalt leading the way. Senior-to-be Sean Westgate should be the other starter, with senior-to-be Glenn Love, sophomore-to-be Isaiah Bowens and maybe a freshman also in the mix.
Replacement quotient: 4 stars

FS Rahim Moore
The buzz: As with Ayers, Moore had a huge 2009 season before backsliding a bit. Junior-to-be Dalton Hilliard backed up Moore this season, but UCLA's top two strong safeties from this season -- Tony Dye and Dietrich Riley -- also appear capable of playing free safety.
Replacement quotient: 4 stars

DT Jurrell Casey
The buzz: Casey was one of the best players in the nation at his position and will be missed. Still, the Trojans should be OK at tackle. Seniors-to-be DaJohn Harris and Hebron Fangupo are the frontrunners to start, and redshirt freshman George Uko arrived highly touted. Coaches also could move Armond Armstead back to tackle from end, and a freshman should get into the mix in the fall.
Replacement quotient: 4 stars

OT Tyron Smith
The buzz: Smith's decision means two of USC's top three tackles need to be replaced. Matt Kalil is a returning starter, and senior-to-be Martin Coleman and sophomore-to-be Kevin Graf are the top candidates to start at the other tackle spot. JC transfer David Garness already is enrolled and will get every opportunity to impress during spring practice.
Replacement quotient: 4 stars

CB Brandon Burton
The buzz: The Utes need to replace both starting corners as they move into the Pac-10. Junior-to-be Reggie Topps and senior-to-be Conroy Black look to be the top contenders among the upperclassmen for the jobs. Redshirt freshman Damian Payne, sophomores-to-be Wykie Freeman and Michael Walker and junior-to-be Ryan Lacy will get a chance to earn time during spring ball.
Replacement quotient: 4 stars

DT Sealver Siligi
The buzz: Siligi's departure, unlike Burton's, was a surprise. Even with his decision, though, Utes coaches have the bodies to choose from at tackle. Dave Kruger, Star Lotulelei, Latu Heimuli, James Aiono, Joape Pela and LT Tuipulotu are the holdovers who will be looking to impress during spring practice, with Kruger and Lotulelei at the head of the line.
Replacement quotient: 3 stars

DE Zane Parr
The buzz: Parr's decision caught most by surprise, as he had just two sacks this season. Virginia looks as if it will be able to replace him quite easily. Sophomore-to-be Jake Snyder and senior-to-be Cameron Johnson -- a returning starter -- likely will be the starting ends. Youngsters such as Will Hill and Justin Renfrow need to impress during spring drills. Coaches also could move starting DT Matt Conrath, who is 6 feet 7, to end.
Replacement quotient: 2 stars

RB Darren Evans
RB Ryan Williams
The buzz: We're grouping these guys together because they played the same position. Tech is going to miss their talent, but the production drop-off might not be as large as you think. The biggest reason for that is Tech's annual emphasis on the run. Another reason is that there still is some talent. Junior-to-be David Wilson should reach 1,000 yards quite easily. Sophomore-to-be Tony Gregory has excellent speed and will get ample opportunity in spring practice to show he should be the No. 2 guy.
Replacement quotient: 4 stars

FS Robert Sands
The buzz: Sands' decision to turn pro means WVU needs two new starting safeties; the Mountaineers run a 3-3-5 set, with three safeties. Senior-to-be Eain Smith -- like Sands, a former south Florida high school star -- would seem to be first in line to be the replacement, but he needs shoulder surgery and is going to miss spring practice. Travis Bell, Darwin Cook and Mike Dorsey are others who will vie for the open safety jobs.
Replacement quotient: 4 stars

RB John Clay
The buzz: If ever there were a team that shouldn't worry about replacing a 1,000-yard rusher, it's the Badgers. James White rushed for more than 1,000 as a true freshman this season, and backup Montee Ball barely missed reaching the plateau. That's a big-time 1-2 punch. Replacing two starters along the offensive line is a much bigger worry than replacing Clay.
Replacement quotient: 2 stars

DE J.J. Watt
The buzz: While Clay won't be missed all that much, Watt's departure hurts. He was overshadowed nationally by numerous others, but he was one of the country's most productive ends this season. Junior-to-be David Gilbert and sophomores-to-be Pat Muldoon and Tyler Dippel will be in the mix to take Watt's spot in the starting lineup. The Badgers should sign at least two ends next month, and one of those could get in the mix during fall drills.
Replacement quotient: 5 stars